Senior React Native & Next.js Engineer | TypeScript, Supabase, Health Platform

**Senior React Native & Next.js Engineer | TypeScript, Supabase, Health Platform** We are looking for a senior full-stack engineer to work across an established health and wellbeing platform consisting of a React Native/Expo mobile app, member-facing functionality, provider and enterprise portals, and a Supabase/PostgreSQL backend. This is an ongoing role within a fast-moving health technology company. You will work in a large TypeScript codebase and will be expected to understand the existing architecture before making changes. The platform handles wearable data, health information, authentication, user consent, portal workflows, dashboards and mobile releases. Reliability, security and disciplined change management are important. **Technology stack** * React Native and Expo * React, Next.js and TypeScript * Supabase and PostgreSQL * Postgres row-level security * REST APIs and real-time data * Authentication and role-based access * Native iOS and Android functionality * TestFlight, App Store Connect and Google Play Console * Git-based development and pull-request workflows **AI-assisted development** You must be experienced using Claude Code and Cursor within existing production repositories. We expect you to use AI coding tools carefully and productively. This includes inspecting the existing implementation, planning changes, reviewing generated code, checking diffs, running tests and validating the finished work. You must be able to explain and defend the code you submit. Large unreviewed AI-generated changes will not be accepted. You will also be expected to follow repository instructions, respect protected components and avoid modifying core authentication, consent, database or health-data workflows without approval. **Responsibilities** * Maintain and extend the React Native/Expo mobile application * Build and improve member, provider and enterprise portal functionality * Develop TypeScript services, API integrations and Supabase functions * Design and review PostgreSQL schemas, migrations and RLS policies * Diagnose mobile, web, backend and data issues * Work with wearable and health-data integrations * Prepare and manage TestFlight and Google Play releases * Write automated tests for important workflows * Review existing code before proposing refactors * Document technical decisions and implementation changes * Submit focused pull requests with clear testing evidence * Identify security, performance and maintainability risks **Essential experience** * Five or more years of professional software development experience * Strong commercial TypeScript experience * Production React Native and Expo experience * Production Next.js and React experience * Strong Supabase and PostgreSQL knowledge * Practical experience implementing and testing Postgres RLS * Experience with authentication and role-based permissions * Experience shipping mobile applications through TestFlight and Google Play * Experience working safely in large, existing codebases * Strong Git, pull-request and code-review practices * Daily working knowledge of Claude Code, Cursor or comparable AI coding environments * Clear written and spoken English **Highly desirable** * Bluetooth Low Energy and wearable-device integration * Background sync, reconnection and mobile permission handling * Health, wellness, aged-care or regulated-data experience * Experience with real-time dashboards and time-series data * CI/CD and automated release workflows * Privacy-by-design and secure development experience **Working approach** We want a disciplined engineer who makes focused, testable changes. You should be comfortable asking questions when requirements are unclear and raising risks before altering sensitive systems. You will work independently while communicating regularly with product leadership. You must provide concise progress updates, identify blockers early and document what was changed and how it was tested. The initial engagement will be a paid technical onboarding and codebase assessment, followed by ongoing development if the engagement is successful. When applying, please answer every screening question and provide evidence from projects you personally worked on. Generic proposals that do not address the questions will not be shortlisted.